I took your advice and added the “Click here” part anyway – in rare circumstances it is OK to exhort people to “Click Here” in a link or button if it is super important and part of the critical path, and signup definitely is.
And perhaps other people have misconfigured monitors and won’t see the “button”, either…
…and soon certain UX designers will come out of the woodwork and complain how you shouldn’t include the phrase “click here” in link text… (I’m fine with that text, BTW).
Given that it is the main call to action on that page, I don’t think it would hurt to use the more bold styling that the reply button I see right below this compose window has. And perhaps add a glyph to make it more button-y (fa rocket 
–as in getting your account “launched”–maybe?)
But as you indicate, it’s probably no biggie.
We could make it the btn-primary color too now that I think about it. Let me do that.